DE2823118A1 - PROCESS FOR THE PRODUCTION OF ORGANOPOLYSILOXANE RESINS CONTAINING SIC-BONDED VINYL GROUPS - Google Patents

Description

282311a

VACKER-CHEMIE Munich, March 21, 1978

GMBH LC-PAT / Dr.Ru / m

Va 7801

Process for the production of SiC-bonded vinyl groups containing organopolysiloxane resins

For example, U.S. Patent 35 4-6 156, issued December 8th 1970, J. Baronnier et al., Assignors to Rhone-Poulenc, where This patent corresponds to PE-PS 15 68 812, it is "known to use SiC-bonded organopolysiloxane resins containing vinyl groups to manufacture. In this known method, silanes containing various organic Residues and hydrolyzed with different functionality in a certain area, and it becomes organopolysiloxane resins obtained, which are practically free of Si-bonded hydroxyl groups and therefore very stable in storage and after Hardening free of cavities. Are. Compared to this method, the inventive method has the advantage that the thereafter resins produced do not contain at least 25 mol percent of the relatively difficult to access diphenylsiloxane units Must contain in order to be flowable. be. Compared to the known method, the method according to the invention has in addition, at least the further advantage that at least a large part of the for the Production of the organopolysiloxane resin used silanes on a large scale Silanes containing various organic residues and with different functionality in

909848/0373

-4- 282311a

must be used in a required area. After this The method according to the invention can thus be carried out with less effort Organopolysiloxane resins are produced with various proportions of SiC-bonded vinyl groups.

The organopolysiloxane resins prepared according to the invention are also practically free of Si-bonded hydroxyl groups.

The invention relates to a process for the production of organopolysiloxane resins containing SiC-bonded vinyl groups, characterized in that a mixture of (A) organopolysiloxane containing at least 0.1 percent by weight of Si-bonded hydroxyl groups with at least 50 mol percent monoorganosiloxane units, (B) organosiloxane with 2 " up to 10 silicon atoms per molecule, in which at least essentially all silicon valencies other than those saturated by siloxane oxygen atoms are saturated by -SiC-bonded hydrocarbon radicals, and on average at least 2 such hydrocarbon radicals are present per Si atom, with at least one of the reactants (A) and (B) contains an average of at least one SiC-bonded vinyl group, and (C) acid-activated fuller's earth is ^{heated to 90 £ 5 0} C, with water released by condensation of Si-bonded hydroxyl groups being left in the reaction residue during this heating, and after heating Organopo lysiloxane. is separated from the fuller's earth.

The organopolysiloxanes (A) used in the context of the invention can, in addition to the monoorganosiloxane units (RSiO, y ₂ » ^E " hydrocarbon radical), for example, up to 50 mol percent diorganosiloxane units (RgSiO, where E has the meaning given above) and up to 10 mol percent each of triorganosiloxane units ( R ₃₅ SiO ₁₁ / p, where R again has the meaning given above). And / or

9098U / 9378

^ / ₂ units included. The organopolysiloxanes (A) used in the context of the invention can, however, also contain, in addition to the monoorganosiloxane units and optionally at least one type of the other aforementioned siloxane units, _{for example O ^ Z 2} SiCH ₂ CH ₂ SiO _{1, 2 units.}

Examples of SiC-bonded hydrocarbon radicals in the organopolysiloxanes (A) and thus for radicals R in the formulas given above are alkyl radicals, such as the methyl, ethyl, n-propyl and isopropyl radical; Alkenyl radicals, such as the vinyl radical; and aryl radicals, such as the phenyl radical. In particular because of the easier accessibility, preferably at least 80 % of the number of SiC-bonded hydrocarbon radicals in the organopolysiloxanes (A) are methyl radicals and at most 5 % of the number of SiC-bonded hydrocarbon radicals in the organopolysiloxanes (A) are phenyl radicals. It is also preferred that the SiC-bonded hydrocarbon radicals. % η organopolysiloxane (A) are all free of aliphatic multiple bonds.

The organopolysiloxanes (A) can, for example, by hydrolysis of at least one organosilane of the general formula

RSiX,,

where X are identical or different hydrolyzable groups, e.g. an ethoxy group, or identical or different hydrolyzable Atoms, in particular chlorine, is, and R, which has the meaning given above for this, optionally in a mixture with up to 50 mole percent, based on the total mole amount of the respective Silangemisch.es, at least one organosilane of the general formula

R ₂ SiX ₂

/ 6 Ö098A8 / 0378

where R and X each have the meaning given above have, and both R and X can be the same or different, in each case up to 10 mol percent, based on the total molar amount of the respective silane mixture, at least one organosilane of the general formula

R ₃ SiX,

where R and X each have the meaning given above, and the groups R can be identical or different, and / or at least one silane of the general formula

SiX ₄ ,

where X has the meaning given above and can be identical or different, or also at least one SiI-carban the general ^ formula

X ^ SiCH ₀ CH ₀ SiX _x ,

in which X has the meaning given above and can be the same or different.

Only one kind of organopolysiloxane (A) can be used. However, different types of organopolysiloxanes (A) can also be used. The organopolysiloxanes (A) usually contain at least 0.2 percent by weight. Si-bonded hydroxyl groups. . _T

The organosiloxanes (B) with 2 to 10 silicon atoms per molecule, in which at least essentially all other than by siloxane- oxygen atoms saturated silicon valences by SiC-bonded Hydrocarbon radicals are saturated, and an average of at least 2 such hydrocarbon radicals each Si atom present can be linear, cyclic or branched

/ 7

909848/0378

be. The examples given above for SiC-bonded hydrocarbons residues in organopolysiloxane (a) also apply in full to the hydrocarbon residues in organopolysiloxane (B). However, it is preferred that in at least 30% of the number of molecules of organopolysiloxane (B) at least There are 2 vinyl groups per molecule, as in the organo siloxanes of the formulas

(CH ₂ = CH) ₂ CH ^ SiOSiOH, (CH = CH ₂ )

[[CH ₂ = CH (CH ₅ ) SiO ^

CH ₅ Si [IOSi (CH ₅ )

where η is an integer ranging from 1 to 10.

A preferred organopolysiloxane (B) with vinyl groups is 1,3-divinyl-1,1 ^ »3-tetramethyldisiloxane.

An example of an organopolysiloxane (B), its hydrocarbon radicals are free of aliphatic multiple bonds, especially in a mixture with vinyl groups Organopolysiloxane (B) that can be used is hexamethyldisiloxane.

As can already be seen from the above, only one can Kind of organosiloxane (B) can be used. But it can

809848/8376

also, different types of organosiloxane (B) can be used.

Organopolysiloxane (B) is preferably used in amounts of 2 to 100 percent by weight, in particular 5 to 50 percent by weight, based in each case on the weight of organopolysiloxane (A), with the proviso that the amount of triorganosiloxane units is at most 15 mol percent of the total amount of siloxane units in Organopolysiloxane (A) and (B). The higher the amount of organosiloxane (B) and the greater the proportion of triorganosiloxane units in organosiloxane (B), the lower, for example 50 to 2,500 mPa-s at 25 ⁰ C, the viscosity of the organopolysiloxane resin is finally obtained.

The preferred example of an acid activated fuller's earth (0) is commercially available and has the following characteristics:

Bulk weight: 4-50 g / l,

Vibration weight: 670 g / l,

Specific weight: 2.4 kg / 1,

Moisture content '(2 h, 110 ⁰ C): at most 7 weight percent, loss on ignition: (1000 ⁰ C): at most 7 weight percent,

pH in 10 percent by weight aqueous suspension: 2.9

This bleaching earth is made of silicon dioxide, aluminum oxide, iron (III) oxide, magnesium oxide, sodium oxide and potassium oxide built up, and 97 percent by weight of this fuller's earth go through a sieve with a mesh size of 150 micrometers.

Numerous other acid activated bleaching earths are below a variety of names, such as "! Perrana (register-

909848/0376

282311a

tes trademark) L 80 "," Tonsil (registered trademark) AC ¹¹ , "Clarit (registered trademark) Standard A", "Nordal" (registered trademark), "Filtrol (registered trademark) ultra" and "Rumsil" (registered trademark) , commercially available and also suitable for the process according to the invention.

Only one type of acid activated fuller's earth can be used. But there can also be different types of acid-activated Bleaching earth can be used.

Acid-activated fuller's earth (O) is preferably used in amounts of 1 "to 5 percent by weight, based on the total weight of substances (A) and (B) are used.

The heating in the inventive method is, because this requires the least effort, preferably when _u pressure of the surrounding atmosphere, ie at about 1 bar or bar Λ performed. Palls are desirable, but higher pressures can also be used.

The duration of the heating in the process according to the invention is preferably 0.5 to 2 hours.

As long as the viscosity of the finally obtained Orgänopolysiloxanharzes not more than 3000 mPa sec at 25 * C ^0, it is preferably separated as such, ie, in undiluted form, by filtration, for example by means of a filter press, from which, bleaching earth. If the organopolysiloxane finally obtained has a viscosity higher than 3000 mPa · s at 25 ° C. or if it is even solid at room temperature, it can be taken up in a solvent such as toluene and / or erichlorethylene before filtering and the solvent after filtering distilled off '".

909848 / Θ376

282311a

The SiC-bonded vinyl groups produced according to the invention containing organopolysiloxane resins are suitable e.g. for encasing electrical insulation, for producing moldings, including the manufacture of trays for dental impressions and for the manufacture of coatings.

The organopolysiloxane resins prepared according to the invention can e.g. by means of peroxidic compounds or by adding organopolysiloxane with Si-bonded hydrogen and the addition of Si-bonded hydrogen to aliphatic multiple bond promoting catalyst, such as a reaction product from H2PtClg-6H20 and cyclohexanone, in a known manner hardened.

In the following examples, all percentages are based on weight, unless otherwise stated. .. _IC , "- ..

example 1

In a three-necked flask equipped with a ground-in stirrer, a thermometer, which is connected to a temperature control device, and a reflux condenser, 600 g of an organopolysiloxane of 80 mol percent monomethylsiloxane units (CH ^ SiO,, ^) and 20 mol percent dimethylsiloxane units with a viscosity of 61,000 mPa * s at 25 ^° C. and 0.78% Si-bonded hydroxyl groups as organopolysiloxane (A) mixed with 69 g of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane as organosiloxane (B) and heated to 90 ^° C. warmed up. ~ After the temperature had steadily adjusted to 90 ± 2 ⁰ C, 17 g (about 2 % ₉ based on the total weight of the two organosiloxanes) of acid-activated fuller's earth with the above-mentioned parameters were added The mixture obtained in this way is added for one hour at 90 ° + 2 ⁰ C and stirred

909848/0376

Exempt 1, diluted with toluene, filtered and concentrated on a rotary evaporator at a bath temperature of 120 ⁰ C, first at 12 mm Hg and then for 1 hour in an oil pump vacuum of volatile constituents: then in Volttmenverhältnis 1 (abs.).

Beistdel 2

The procedure described in Example 1 is repeated with the changes that as organosiloxane (B) instead of 69 g of 1, ^ - divinyl-ijijJ ^ -tetramethyldisiloxane 75 g of this Bisiloxane and 60 g hexamethyldisiloxane are used, and because of the relatively low viscosity of the organopolysiloxane finally obtained, it is filtered while it is still hot without prior dilution so that no volatile constituents have to be distilled off afterwards either.

- β. - k .;

Example 3

The procedure described in Example 1 is repeated with the changes that the organopolysiloxane (A) instead of the 600 g of the organopolysiloxane consists of 80 mol percent monomethylsiloxane units and 20 mol percent dimethylsiloxane units with a viscosity of 61,000 mPas at 25 ^° C. and 0.78 # Si -Bound hydroxyl groups 480 g of this organopolysiloxane and 120 g of an organopolysiloxane of 50 mol percent monomethylsiloxane units and 50 mol percent dimethylsiloxane units with a viscosity of 1590 mPa ^% s at 25 _V ° C and 0.49 % Si-bonded hydroxyl groups are used, and because of the relatively low Viscosity of the organopolysiloxane finally obtained this is filtered while still hot, without prior dilution.

109848/8376

Example 4

The procedure described in Example 1 is repeated with the modifications that instead of the 600 g of the organopolysiloxane, the organopolysiloxane consists of 80 mol percent monomethylsiloxane units and 20 mol percent dimethylsiloxane units with a viscosity of 61,000 mPa.s at 25 ^° C. and 0.78 % Si-bonded hydroxyl groups 360 g of this organopolysiloxane and 240 g of the organopolysiloxane of 50 mol percent monomethylsiloxane units and 50 mol percent dimethylsiloxane units with a viscosity of 1590 mPa · s at 25 ⁰ C and 0.49 % Si-bonded hydroxyl groups are used, and the filtration of the organopolysiloxane finally obtained as in Examples 2 and 3 are carried out without prior dilution.

Example 5 - tr

The procedure described in Example 1 is repeated with the modification that 82 g of i ^ -Divinyl-iji ^^ - tetramethyldisiloxane can be used in place of the 69 g of this disiloxane.

Example 6

The procedure described in Example 1 is repeated with the modification that 103 g of 1 ^ -divinyl-i ^ i ^^ - tetramethyldisiloxane can be used in place of the 69 g of this disiloxane.

The organopolysiloxane resins containing Si-bonded vinyl groups prepared according to Examples 1 to 6 all contain less than 0.1 % Si-bonded hydroxyl groups. The viscosities of these resins are given in the following table:

/ 13 909848/8378

Tabel

example viscosity mPa's 1 44000 2 2700 3 2500 4th 910 5 8400 6th 3600

909343/8378

Claims (3)

Patent claims Process for the production of organopolysiloxane resins containing SiC-bonded vinyl groups, characterized in that a mixture of (A) organopolysiloxane containing at least 0.1% by weight of Si-bonded hydroxyl groups with at least 50 mole percent monoorganosiloxane units, (B) organosiloxane with 2 to 10 silicon atoms per molecule, in which at least essentially all silicon valencies other than by siloxane oxygen atoms are saturated by SiC-bonded hydrocarbon radicals, and on average at least 2 such hydrocarbon radicals are present per Si atom, with at least one of the reactants (A) and (B) on average at least one SiC-bonded vinyl group , and (C) acid-activated bleaching earth is heated to 90 J ₁ 5 ⁰ C, said free become water is left in the reaction mixture during this heating, by condensation of Si-bonded hydroxyl groups, and abgetr after heating organopolysiloxane of the bleaching earth is ennt. 2. The method according to claim 1, characterized in that the SiC-bonded hydrocarbon radicals in organopolysiloxane (A) are all free of aliphatic multiple bonds, and in at least 30 % of the number of molecules of organopolysiloxane (B) at least 2 vinyl groups per molecule are present. 3. The method according to claim 1 and 2, characterized in that the organosiloxane (B) 1,3-divinyl-1,1,3 j 3-tetramethyldi-siloxane is used will. 72 9 098A8 / 3378 QFHGJNAL JNSPECTED Process according to Claims 1 to 5 »characterized in that the acid-activated
Fuller's earth is used in amounts of 1 to 5 percent by weight, based on the total weight of substances (A) and (B). 909848/0376